Add water usage calculation to department daily reports

- Introduced `getTransactionsOnDateWaterUsage` method in `department_daily_reports_o` to calculate water usage based on transactions for a given date or date range.
- Updated department daily reports routes to include `water_usage` in the output.

services/nginx/app/objects/department_daily_reports_o.php

@@ -560,4 +560,59 @@ class department_daily_reports_o extends db
         }
         return (int)$amount;
     }
+
+    /**
+     * This function calculates how much water has been used on the transactions on a given date
+     * That is calculated by getting the water usage report on the earliest report before the given date
+     * and the water usage report on the latest report on or before the given date
+     * The difference between the two is the water usage for the given date
+     * @note This does not count products from removed orders, only products from orders that are still active
+     * @param string $date The date to get the report for (YYYY-MM-DD)
+     * @param int $department_id The id of the department
+     * @param string|null $date_to (Optional) The end date to get the report for (YYYY-MM-DD). If provided, the report will be for the date range between $date and $date_to
+     * @return int The amount of water used on the given date
+     */
+    public function getTransactionsOnDateWaterUsage(string $date, int $department_id, string $date_to = null): int
+    {
+        global /** @var db $db */
+        $db;
+        // If the date_to is null, set it to the date
+        if ($date_to === null) {
+            $date_to = $date; // Making the report for an entire day
+        }
+        $conn = $db->conn();
+        // Get the earliest report before the given date
+        $stmt = $conn->prepare(
+            'SELECT water_usage FROM department_daily_reports o
+                   WHERE o.created_at < ? AND o.department_id = ? AND o.water_usage > 0 ORDER BY o.created_at DESC LIMIT 1'
+        );
+        if ($stmt) {
+            $stmt->bind_param('si', $date, $department_id); // Bind parameters
+            $stmt->execute();
+            $result = $stmt->get_result(); // Get the result set from the statement
+            $data = $result->fetch_assoc(); // Fetch the result as an associative array
+            $earliest_usage = $data ? (int)$data['water_usage'] : 0;
+            $stmt->close(); // Close the statement
+        } else {
+            // Handle query preparation error
+            die('Query preparation failed: ' . $conn->error);
+        }
+        // Get the report closest to the date_to, but not after
+        $stmt = $conn->prepare(
+            'SELECT water_usage FROM department_daily_reports o
+                   WHERE o.created_at <= ? AND o.department_id = ? AND o.water_usage > 0 ORDER BY o.created_at DESC LIMIT 1'
+        );
+        if ($stmt) {
+            $stmt->bind_param('si', $date_to, $department_id); // Bind parameters
+            $stmt->execute();
+            $result = $stmt->get_result(); // Get the result set from the statement
+            $data = $result->fetch_assoc(); // Fetch the result as an associative array
+            $latest_usage = $data ? (int)$data['water_usage'] : 0;
+            $stmt->close(); // Close the statement
+        } else {
+            // Handle query preparation error
+            die('Query preparation failed: ' . $conn->error);
+        }
+        return $latest_usage - $earliest_usage;
+    }
 }

services/nginx/app/routes/departmentDailyReportsRoute.php

@@ -506,6 +506,13 @@ class departmentDailyReportsRoute
                                     (int)self::getParameter('department_id'),
                                     $date_to
                                 ),
+                        'water_usage' =>
+                            (new department_daily_reports_o())
+                                ->getTransactionsOnDateWaterUsage(
+                                    (string)self::getParameter('date'),
+                                    (int)self::getParameter('department_id'),
+                                    $date_to
+                                ),
                         'date' => (string)self::getParameter('date'),
                         'department_id' => (int)self::getParameter('department_id'),
                         'date_to' => $date_to,